Herbicidal N-azinyl-N&#39;-(2-ethylsulphinyl-phenylsulphonyl)-ureas

ABSTRACT

Herbicidal N-azinyl-N&#39;-(2-ethylsulphinyl-phenylsulphonyl)ureas of the formula ##STR1## in which A represents nitrogen or a CH group, 
     X represents hydrogen, halogen or alkyl, alkoxy or alkylthio, each of which has 1 to 3 carbon atoms and each of which is optionally substituted by halogen and 
     Y represents alkyl or alkoxy, each of which has 1 to 3 carbon atoms and each of which is optionally substituted by halogen, 
     and salts thereof.

The invention relates to newN-azinyl-N'-(2-ethylsulphinyl-phenylsulphonyl)-ureas, processes fortheir preparation, and their use as herbicides.

It has been disclosed that certain arylsulphonylureas havingsubstituents bonded via sulphur such as, for example,N-(4,6-dimethoxy-s-triazin-2-yl)-N'-(2-propylthio-phenylsulphonyl)-urea(cf. U.S. Pat. No. 4,818,277) orN-(4,6-dimethylpyrimidin-2-yl)-N'-(2-methyl-sulphinylphenylsulphonyl)-urea(cf. U.S. Pat. No. 4,169,719; cf. also EP-A 101,308, EP-A 35,893) haveherbicidal properties. However, the herbicidal action of these knowncompounds is not satisfactory in all respects.

New N-azinyl-N'-(2-ethylsulphinyl-phenylsulphonyl)-ureas of the generalformula (I) ##STR2## in which A represents nitrogen or a CH group,

X represents hydrogen, halogen or alkyl, alkoxy or alkylthio, each ofwhich has 1 to 3 carbon atoms and each of which is optionallysubstituted by halogen and

Y represents alkyl or alkoxy, each of which has 1 to 3 carbon atoms andeach of which is optionally substituted by halogen,

and salts of compounds of the formula (I) have now been found.

The new N-azinyl-N'-(2-ethylsulphinyl-phenylsulphonyl)ureas of thegeneral formula (I) are obtained when

N-azinyl-N'-(2-ethylthio-phenylsulphonyl)-ureas of the general formula(II) ##STR3## in which A, X and Y have the abovementioned meanings

are reacted with hydrogen peroxide (H202) in the presence of a diluent,

and, if appropriate, the products obtained in this way are convertedinto salts by customary methods.

The new N-azinyl-N'-(2-ethylsulphinyl-phenylsulphonyl)ureas of theformula (I) are distinguished by a powerful herbicidal activity.

Surprisingly, the new compounds of the formula (I) show a considerablymore powerful action than the known compoundsN-(4,6-dimethoxy-s-triazin-2-yl)-N'-(2-propylthiophenylsulphonyl)-ureaandN-(4,6-dimethylpyrimidin-2-yl)-N'-(2-methylsulphinyl-phenylsulphonyl)-urea,which are comparable in terms of structure and profile of action.

The invention preferably relates to compounds of the formula (I) inwhich

A represents nitrogen or a CH group,

X represents hydrogen, fluorine, chlorine, bromine, or represents alkyl,alkoxy or alkylthio, each of which has 1 or 2 carbon atoms and each ofwhich is optionally substituted by fluorine and/or chlorine, and

Y represents alkyl or alkoxy, each of which has 1 or 2 carbon atoms andeach of which is optionally substituted by fluorine and/or chlorine.

The invention furthermore preferably relates to salts which are obtainedfrom compounds of the formula (I) and bases such as, for example, sodiumhydroxide, sodium hydride, sodium amide, sodium carbonate, potassiumhydroxide, potassium hydride, potassium amide, potassium carbonate,calcium hydroxide, calcium hydride, calcium amide or calcium carbonate,sodium C₁ -C₄ -alkanolates or potassium C₁ -C₄ -alkanolates, ammonia, C₁-C₄ -alkylamines, di- (C₁ -C₄ -alkyl) -amines or tri- (C₁ -C₄ -alkyl)-amines.

The invention particularly relates to compounds of the formula (I) inwhich

A represents nitrogen or a CH group,

X represents hydrogen, chlorine, methyl, ethyl, methoxy, ethoxy,difluoromethoxy or methylthio and

Y represents methyl, ethyl, trifluoromethyl, methoxy, ethoxy ordifluoromethoxy.

If, for example,N-(4,6-dimethoxy-pyrimidin-2-yl)-N'-(2-ethylthio-phenylsulphonyl)-ureais used as starting substance, the course of the reaction can beoutlined by the following equation: ##STR4##

Formula (II) provides a general def inition of theN-azinyl-N'-(2-ethylthio-phenylsulphonyl)-ureas to be used as startingsubstances in the process according to the invention for the preparationof compounds of the formula (i).

In formula (II) , A, X and Y preferably, or in particular, have thosemeanings which have already been mentioned above in connection with thedescription of the compounds of the formula (I) according to theinvention as being preferred, or particularly preferred, for A, X and Y.

The starting substances of the formula (II) are known and/or can beprepared by processes known per se (cf. U.S. Pat. No. 4,127,405, U.S.Pat. No. 4,169,719).

The process according to the invention is carried out using hydrogenperoxide. The hydrogen peroxide is preferably employed as an aqueoussolution which preferably contains between 5% and 55%, in particularbetween 10% and 50%, of H₂ O₂.

The process according to the invention is carried out in the presence ofa diluent. Diluents which are suitable for this purpose are virtuallyall those which are customary in oxidation reactions. Diluents which arepreferred for the process according to the invention are carboxylicacids such as formic acid, acetic acid and propionic acid, in particularacetic acid.

When carrying out the process according to the invention, the reactiontemperatures can be varied within a substantial range. In general, theprocess is carried out at temperatures between 0° C. and 100° C.,preferably at temperatures between 10° C. and 60° C.

The process according to the invention is generally carried out underatmospheric pressure. However, it is also possible to carry out theprocess under increased or reduced pressure.

For carrying out the process according to the invention, between 1.0 and2.0 moles, preferably between 1.1 and 1.5 moles, of hydrogen peroxideare generally employed per mole of starting compound of the formula(II).

The reactants are preferably reacted as follows: The sulphonylurea ofthe formula (II) is first mixed with the diluent, and the hydrogenperoxide is slowly metered into this mixture, with stirring. Thereaction mixture is then stirred until the reaction is complete, ifappropriate at elevated temperature. When the mixture has cooled it maybe diluted with water, and the crystalline product is then isolated byfiltration with suction.

If appropriate, salts can be prepared from the compounds of the generalformula (I) according to the invention. Such salts are obtained in asimple manner by customary salt formation methods, for example bydissolving or dispersing a compound of the formula (I) in a suitablediluent such as, for example, methylene chloride, tert-butyl-methylether or toluene, and adding a suitable base. The salts can then beisolated by concentration or filtration with suction, if appropriateafter prolonged stirring (cf. the Preparation Examples).

The active compounds according to the invention can be used asdefoliants, desiccants, agents for destroying broad-leaved plants and,especially, as weed-killers. By weeds, in the broadest sense, there areto be understood all plants which grow in locations where they areundesired. Whether the substances according to the invention act astotal or selective herbicides depends essentially on the amount used.

The active compounds according to the invention can be used, forexample, in connection with the following plants:

Dicotyledon weeds of the crenera: Sinapis, Lepidium, Galium, Stellaria,Matricaria, Anthemis, Galinsoga, Chenopodium, Urtica, Senecio,Amaranthus, Portulaca, Xanthium, Convolvulus, Ipomoea, Polygonum,Sesbania, Ambrosia, Cirsium, Carduus, Sonchus, Solanum, Rorippa, Rotala,Lindernia, Lamium, Veronica, Abutilon, Emex, Datura, Viola, Galeopsis,Papaver, Centaurea, Trifolium, Ranunculus and Taraxacum.

Dicotyledon cultures of thi genera: Gossypium, Glycine, Beta, Daucus,Phaseolus, Pisum, Solanum, Linum, Ipomoea, Vicia, Nicotiana,Lycopersicon, Arachis, Brassica, Lactuca, Cucumis and Cucurbita.

Monocotyledon weeds of the genera: Echinochloa, Setaria, Panicum,Digitaria, Phleum, Poa, Festuca, Eleusine, Brachiaria, Lolium, Bromus,Avena, Cyperus, Sorghum, Agropyron, Cynodon, Monochoria, Fimbristylis,Sagittaria, Eleocharis, Scirpus, Paspalum, Ischaemum, Sphenoclea,Dactyloctenium, Agrostis, Alopecurus and Apera.

Monocotyledon cultures of the genera: Oryza, Zea, Triticum, Hordeum,Avena, Secale, Sorghum, Panicum, Saccharum, Ananas, Asparagus andAllium.

However, the use of the active compounds according to the invention isin no way restricted to these genera, but also extends in the samemanner to other plants.

The compounds are suitable, depending on the concentration, for thetotal combating of weeds, for example on industrial terrain and railtracks, and on paths and squares with or without tree plantings.Equally, the compounds can be employed for combating weeds in perennialcultures, f or example af f orestations, decorative tree plantings,orchards, vineyards, citrus groves, nut orchards, banana plantations,cof fee plantations, tea plantations, rubber plantations, oil palmplantations, cocoa plantations, soft fruit plantings and hopfields, inlawns, turf and pasture-land and for the selective combating of weeds inannual cultures.

The compounds of the formula (I) according to the invention areparticularly suitable for selectively combating monocotyledon anddicotyledon weeds in monocotyledon cultures, both by the preemergenceand the postemergence method.

The active compounds can be converted into the customary formulations,such as solutions, emulsions, wettable powders, suspensions, powders,dusting agents, pastes, soluble powders, granules, suspension-emulsionconcentrates, natural and synthetic materials impregnated with activecompound, and very fine capsules in polymeric substances.

These formulations are produced in a known manner, for example by mixingthe active compounds with extenders, that is liquid solvents and/orsolid carriers, optionally with the use of surface-active agents, thatis emulsifying agents and/or dispersing agents and/or foam-formingagents.

In the case of the use of water as an extender, organic solvents can,for example, also be used as auxiliary solvents. As liquid solvents,there are suitable in the main: aromatics, such as xylene, toluene, oralkylnaphthalenes, chlorinated aromatics and chlorinated aliphatichydrocarbons, such as chlorobenzenes, chloroethylenes or methylenechloride, aliphatic hydrocarbons, such as cyclohexane or paraffins, forexample petroleum fractions, mineral and vegetable oils, alcohols, suchas butanol or glycol as well as their ethers and esters, ketones, suchas acetone, methyl ethyl ketone, methyl isobutyl ketone orcyclohexanone, strongly polar solvents, such as dimethylformamide anddimethyl sulphoxide, as well as water.

As solid carriers there are suitable: for example ammonium salts andground natural minerals, such as kaolins, clays, talc, chalk, quartz,attapulgite, montmorillonite or diatomaceous earth, and ground syntheticminerals, such as highly disperse silica, alumina and silicates; assolid carriers for granules there are suitable: for example crushed andfractionated natural rocks such as calcite, marble, pumice, sepioliteand dolomite, as well as synthetic granules of inorganic and organicmeals, and granules of organic material such as sawdust, coconut shells,maize cobs and tobacco stalks; as emulsifying and/or foam-forming agentsthere are suitable: for example non-ionic and anionic emulsifiers, suchas polyoxyethylene fatty acid esters, polyoxyethylene fatty alcoholethers, for example alkylaryl polyglycol ethers, alkylsulphonates, alkylsulphates, arylsulphonates as well as albumen hydrolysis products; asdispersing agents there are suitable: for example lignin-sulphite wasteliquors and methylcellulose.

Adhesives such as carboxymethylcellulose and natural and syntheticpolymers in the form of powders, granules or latexes, such as gumarabic, polyvinyl alcohol and polyvinyl acetate, as well as naturalphospholipids, such as cephalins and lecithins, and syntheticphospholipids, can be used in the f ormu.lations. Further additives canbe mineral and vegetable oils.

It is possible to use colorants such as inorganic pigments, for exampleiron oxide, titanium oxide and Prussian Blue, and organic dyestuffs,such as alizarin dyestuffs, azo dyestuffs and metal phthalocyaninedyestuffs, and trace nutrients such as salts of iron, manganese, boron,copper, cobalt, molybdenum and zinc.

The formulations in general contain between 0.1 and 95 per cent byweight of active compound, preferably between 0.5 and 90%.

For combating weeds, the active compounds according to the invention, assuch or in the form of their formulations, can also be used as mixtureswith known herbicides, finished formulations or tank mixes beingpossible.

Suitable components for the mixtures are known herbicides, such as, forexample, anilides such as, for example, diflufenican and propanil;arylcarboxylic acids such as, for example, dichloropicolinic acid,dicamba and picloram; aryloxyalkanoic acids such as, for example, 2,4 D,2,4 DB, 2,4 DP, fluroxypyr, MCPA, MCPP and triclopyr;aryloxy-phenoxy-alkanoates such as, for example, diclofop-methyl,fenoxaprop-ethyl, fluazifopbutyl, haloxyfop-methyl and quizalofop-ethyl;azinones such as, for example, chloridazon and norflurazon; carbamatessuch. as, for example, chlorpropham, desmedipham, phenmedipham andpropham; chloroacetanilides such as, for example, alachlor, acetochlor,butachlor, metazachlor, metolachlor, pretilachlor and propachlor;dinitroanilines such as, for example, oryzalin, pendimethalin andtrifluralin; diphenyl ethers such as, for example, acifluorfen, bifenox,fluoroglycofen, fomesafen, halosafen, lactofen and oxyfluorfen, ureassuch as, for example, chlortoluron, diuron, fluometuron, isoproturon,linuron and methabenzthiazuron; hydroxylamines such as, for example,alloxydim, clethodim, cycloxydim, sethoxydim and tralkoxydim;imidazolinones such as, for example, imazethapyr, imazamethabenz,imazapyr and imazaquin; nitriles such as, for example, bromoxynil,dichlobenil and ioxynil; oxyacetamides such as, for example, mefenacet;sulphonylureas such as, for example, amidosulfuron, bensulfuron-methyl,chlorimuronethyl, chlorsulfuron, cinosulfuron, metsulfuron-methyl,nicosulfuron, primisulfuron, pyrazosulfuron-ethyl,thifensulfuron-methyl, triasulfuron and tribenuronmethyl; thiocarbamatessuch as, for example, butylate, cycloate, di-allate, EPTC, esprocarb,molinate, prosulfocarb, thiobencarb and tri-allate; triazines such as,for example, atrazine, cyanazine, simazine, simetryne, terbutryne andterbutylazine; triazinones such as, for example, hexazinone, metamitronand metribuzin; others such as, for example, aminotriazole, benfuresate,bentazone, cinmethylin, clomazone, clopyralid, difenzoquat, dithiopyr,ethofumesate, fluorochloridone, glufosinate, glyphosate, isoxaben,pyridate, quinchlorac, quinmerac, sulphosate and tridiphane.

Mixtures with other known active compounds, such as fungicides,insecticides, acaricides, nematicides, bird repellants, plant nutrientsand agents which improve soil structure, are also possible.

The active compounds can be used as such, in the form of theirformulations or in the use forms prepared therefrom by further dilution,such as ready-to-use solutions, suspensions, emulsions, powders, pastesand granules. They are used in the customary manner, for example bywatering, spraying, atomising or scattering.

The active compounds according to the invention can be applied eitherbefore or after emergence of the plants. They can also be incorporatedinto the soil before sowing.

The amount of active compound used can vary within a substantial range.It depends essentially on the nature of the desired effect. In general,the amounts used are between 10 g and 10 kg of active compound perhectare of soil surface, preferably between 50 g and 5 kg per ha.

The preparation and use of the active compounds according to theinvention can be seen from the following examples.

PREPARATION EXAMPLES EXAMPLE 1 ##STR5##

A mixture of 16 g (0.04 mol) ofN-(4,6-dimethoxy-s-triazin-2-yl)-N'-(2-ethylthio-phenylsulphonyl)-urea,70 ml of acetic acid and 6 ml of a 30% strength aqueous solution ofhydrogen peroxide (0.06 mol of H₂ O₂) is stirred for 18 hours at 22° C.After an addition of 120 ml of water, the product which has beenobtained in the form of crystals is isolated by filtration with suction.

14 g (84% of theory) ofN-(4,6-dimethoxy-s-triazin-2-yl)-N'-(2-ethylsulphinyl-phenylsulphonyl)-ureaof melting point 165° C. are obtained.

Salts of compounds of the formula (I): EXAMPLE 4a ##STR6##

0.5 g (0.01 mol) of 80% sodium hydroxide powder is added, with stirring,to a mixture of 3.9 g (0.01 mol) ofN-(4,6-dimethyl-pyrimidin-2-yl)-N'-(2-ethylsulphinylphenylsulphonyl)-ureaand 100 ml of toluene. The mixture is stirred for 15 hours at 20° C.;the crystalline product is subsequently isolated by filtration withsuction.

4.0 g (99% of theory) of the sodium salt ofN-(4,6-dimethyl-pyrimidin-2-yl)-N'-(2-ethylsulphinyl-phenylsulphonyl)-ureaof melting point 105° C. are obtained (with decomposition).

Other compounds of the formula (I) or their salts which can be preparedanalogously to Example 1 or Example 4a and following the generaldescription of the preparation process according to the invention are,for example, those mentioned in Table 1 below.

                  TABLE 1                                                         ______________________________________                                         ##STR7##                     (I)                                             Examples of the compounds of the formula (I)                                  and their salts                                                               Ex.                                    Melting                                No.  A      X         Y       Salt     point (°C.)                     ______________________________________                                        2    N      OCH.sub.3 CH.sub.3                                                                              --       109                                    3    CH     OCH.sub.3 OCH.sub.3                                                                             --       187                                    1a   N      OCH.sub.3 OCH.sub.3                                                                             sodium salt                                                                            190                                    2a   N      OCH.sub.3 CH.sub.3                                                                              sodium salt                                                                            200                                    3a   CH     OCH.sub.3 OCH.sub.3                                                                             sodium salt                                                                            185                                    4    CH     CH.sub.3  CH.sub.3                                                                              --       135                                    5    CH     OCH.sub.3 CH.sub.3                                                                              --       182                                    5a   CH     OCH.sub.3 CH.sub.3                                                                              sodium salt                                                                            148                                    6    CH     Cl        OCH.sub.3                                                                             --       204                                    6a   CH     Cl        OCH.sub.3                                                                             sodium salt                                                                            155                                    7    CH     Cl        OC.sub.2 H.sub.5                                                                      --       148                                    7a   CH     Cl        OC.sub.2 H.sub.5                                                                      sodium salt                                                                             80                                    8    N      OCH.sub.3 OC.sub.2 H.sub.5                                                                      --       167                                    8a   N      OCH.sub.3 OC.sub.2 H.sub.5                                                                      sodium salt                                                                            137                                    9    CH     H         CH.sub.3                                                                              --       192                                    9a   CH     H         CH.sub.3                                                                              sodium salt                                                                            170                                    10   CH     OC.sub.2 H.sub.5                                                                        OC.sub.2 H.sub.5                                                                      --       142                                    10a  CH     OC.sub.2 H.sub.5                                                                        OC.sub.2 H.sub.5                                                                      sodium salt                                                                            110                                    11   N      CH.sub.3  CH.sub.3                                                                              --       146                                    11a  N      CH.sub.3  CH.sub.3                                                                              sodium salt                                                                            170                                    12   CH     C.sub.2 H.sub.5                                                                         OCH.sub.3                                                                             --                                              13   CH     OC.sub.2 H.sub.5                                                                        CH.sub.3                                                                              --                                              14   CH     OCH.sub.3 CF.sub.3                                                                              --                                              15   N      OCH.sub.3 CF.sub.3                                                                              --                                              16   N      OC.sub.2 H.sub.5                                                                        CH.sub.3                                                                              --                                              17   N      C.sub.2 H.sub.5                                                                         OCH.sub.3                                                                             --                                              18   CH     OCHF.sub.2                                                                              OCHF.sub.2                                                                            --                                              19   CH     SCH.sub.3 CH.sub.3                                                                              --                                              20   CH     SCH.sub.3 C.sub.2 H.sub.5                                                                       --                                              21   N      SCH.sub.3 CH.sub.3                                                                              --                                              22   CH     Cl        CH.sub.3                                                                              --                                              23   N      SCH.sub.3 OCH.sub.3                                                                             --                                              24   N      Cl        CH.sub.3                                                                              --                                              ______________________________________                                    

USE EXAMPLES

In the use examples which follow, the compounds mentioned below are usedas comparison substances: ##STR8##N-(4,6-dimethoxy-s-triazin-2-yl)-N'-(2-propylthio-phenylsulphonyl)-urea(disclosed in U.S. Pat. No. 4,818,277); ##STR9##N-(4,6-dimethyl-pyrimidin-2-yl)-N'-(2-methylsulphinylphenylsulphonyl)-urea(disclosed in U.S. Pat. No. 4,169,719).

EXAMPLE A Preemergence test

Solvent: 5 parts by weight of acetone

Emulsifier: 1 part by weight of alkylaryl polyglycol ether

To produce a suitable preparation of active compound, 1 part by weightof active compound is mixed with the stated amount of solvent, thestated amount of emulsifier is added and the concentrate is diluted withwater to the desired concentration.

Seeds of the test plants are sown in normal soil and, after 24 hours,watered with the preparation of the active compound. It is expedient tokeep constant the amount of water per unit area. The concentration ofthe active compound in the preparation is of no importance, only theamount of active compound applied per unit area being decisive. Afterthree weeks, the degree of damage to the plants is rated in % damage incomparison to the development of the untreated control. The figuresdenote:

0% =no action (like untreated control)

100% =total destruction

A clearly superior activity compared with the prior art is shown, inthis test, for example by the compounds of the following PreparationExamples: 2a, 3, 3a, 4, 4a, 5 and 5a.

EXAMPLE B Post-emergence test

Solvent: 5 parts by weight of acetone

Emulsifier: 1 part by weight of alkylaryl polyglycol ether

To produce a suitable preparation of active compound, 1 part by weightof active compound is mixed with the stated amount of solvent, thestated amount of emulsifier is added and the concentrate is diluted withwater to the desired concentration.

Test plants which have a height of 5-15 cm are sprayed with thepreparation of the active compound in such a way as to apply theparticular amounts of active compound desired per unit area. Theconcentration of the spray liquor is so chosen that the particularamounts of active compound desired are applied in 1,000 1 of water/ha.After three weeks, the degree of damage to the plants is rated in %damage in comparison to the development of the untreated control. Thefigures denote:

0% =no action (like untreated control)

100% =total destruction

A clearly superior activity compared with the prior art is shown, inthis test, for example by the compounds of the following PreparationExamples: 1, 2 and 3.

It will be understood that the specification and examples areillustrative but not limitative of the present invention and that otherembodiments within the spirit and scope of the invention will suggestthemselves to those skilled in the art.

We claim:
 1. An N-azinyl-N'-(2-ethylsulphinyl-phenylsulphonyl)urea ofthe formula ##STR10## in which A represents a CH group,X representshydrogen, halogen or alkyl, alkoxy or alkylthio, each of which has 1 to3 carbon atoms and each of which is optionally substituted by halogenand Y represents alkyl or alkoxy, each of which has 1 to 3 carbon atomsand each of which is optionally substituted by halogen,or a saltthereof.
 2. An urea according to claim 1 or a salt thereof, in whichArepresents a CH group, X represents hydrogen, fluorine, chlorine,bromine, or represents alkyl, alkoxy or alkylthio, each of which has 1or 2 carbon atoms and each of which is optionally substituted byfluorine and/or chlorine, and Y represents alkyl or alkoxy, each ofwhich has 1 or 2 carbon atoms and each of which is optionallysubstituted by fluorine and/or chlorine.
 3. An urea according to claim 1or a salt thereof, in whichA represents a CH group, X representshydrogen, chlorine, methyl, ethyl, methoxy, ethoxy, difluoromethoxy ormethylthio and Y represents methyl, ethyl, trifluoromethyl, methoxy,ethoxy or difluoromethoxy.
 4. The sodium salt ofN-(4,6-dimethoxy-pyrimidin-2-yl)-N'-(2-ethylsulphinyl-phenylsulphonyl)-urea,of the formula ##STR11## according to claim
 1. 5. A herbicidalcomposition comprising a herbicidally effective amount of an urea or asalt thereof according to claim 1 and a diluent.
 6. A method ofcombating unwanted vegetation which comprises applying to suchvegetation or to a locus from which it is desired to exclude suchvegetation a herbicidally effective amount of an urea or salt thereofaccording to claim
 1. 7. The method according to claim 6, wherein suchcompound is the sodium salt ofN-(4,6-dimethoxy-pyrimidin-2-yl)-N'-(2-ethylsulphinyl-phenylsuphonyl)-urea